>> piggyback what jim said, the tremendous amount of information. it's really hard to conceptualize how much is going on, how many streams of information are coming in. big part of it right now, of course, lining up witnesses with all the data that's available. digital and analog. and identifying people, timeline, sequences. who was here, egress routes? as far as facial recognition system, i've been out of the government now for about 18 months, and before that, there were huge leaps in technology and biometrics and facial recognition system. i can imagine now the state-of-the art is that much further along. i'm sure it will be a big part in helping identify. >> when we talk about this mounds and mounds of evidence, it's really two different crime scenes essentially. we had two bomb sites. are they treating each of these independently or look for commonalities between the two? >> absolutely on the commonalities. think of it in terms of one major crime scene, death scene here, with some of the best technicians in all of law enforcement anywhere. goin